Secretary of State Hillary Clinton headed to China Tuesday as US officials raced to find a solution to a sensitive row over a top dissident reportedly holed up at the US embassy in Beijing.

Clinton and Treasury Secretary Timothy Geithner had long planned to go to Beijing for the annual meeting between the world's two largest economies that now is likely to be overshadowed by the case of blind activist Chen Guangcheng.

Chen, who riled authorities by exposing forced abortions and sterilizations under China's one-child policy, made a daring escape last week from house arrest and, according to fellow activists, took refuge in the US embassy.

US officials have kept an unusually solid wall of secrecy over the case, refusing even to say Chen's name. But President Barack Obama and Clinton both said Monday that they would press for human rights in China.

"A constructive relationship includes talking very frankly about those areas where we do not agree, including human rights. That is the spirit that is guiding me as I take off for Beijing," Clinton said.

Clinton left Washington shortly before midnight Monday (0400 GMT Tuesday).

Experts said they saw few easy ways to resolve the case of Chen, who has said that he and his wife suffered severe beatings for defiantly speaking out after he completed a four-year jail sentence.

Chen, 40, is said to want to stay in China, but US officials would be loath to hand him over without iron-clad safety guarantees.

Kenneth Lieberthal, a China expert who was a top aide to president Bill Clinton, said he believed the United States wanted a solution that is "the least embarrassing to China and to do so as expeditiously as possible."

"The question to my mind is whether in China this turns into a political football in a very political season. I think it's more likely to be resolved than to turn into a political football, but you never can predict this stuff," said Lieberthal, a senior fellow at the Brookings Institution.

China is preparing for a once-in-a-decade political handover, with the communist leadership eager to preserve calm as Vice President Xi Jinping prepares to succeed President Hu Jintao.

The facade of a smooth transition was already shattered when rising star Bo Xilai was dramatically ousted from China's inner circle in a scandal that involved his right-hand man seeking refuge -- unsuccessfully -- at a US consulate.

In the United States, where the 2012 campaign is well under way, White House hopeful Mitt Romney has sharply criticized Obama's China policy, saying he should challenge the rising Asian power more aggressively over its human rights record, trade practices and military expansion.

Before the Chen case, Obama administration officials had hoped to showcase small signs of progress in relations with China at the Strategic and Economic Dialogue, which takes place Thursday and Friday.

Largely in response to inflationary pressure, China has let its yuan appreciate. US lawmakers have long accused Beijing of keeping the value of the yuan artificially low to flood the world with cheap exports.

China has also in recent weeks reduced imports of oil from Iran, spoken out -- albeit cautiously -- against a rocket launch by North Korea and backed a peace plan for Syria after joining Russia in vetoing two UN resolutions.

South Sudan said that China, a major oil importer, would lend the new nation $8 billion despite Beijing's longstanding ties to Khartoum.

The US pointman on Sudan, Princeton Lyman, is joining Clinton to seek China's help in ending recent fighting.

"Up until now, in the last few months, things have been going pretty well in the relationship," said Nina Hachigian, a senior fellow at the Center for American Progress, a left-leaning think tank.

But Hachigian said China's human rights record was one area without positive developments and that Chen's case "is obviously going to affect the aura in which the talks are being held."

Clinton will head from China to Bangladesh and then India, as part of US efforts to build relations with the world's other billion-plus nation.

Clinton met Monday with officials from key allies the Philippines and Japan, throwing a gala dinner for Japan's Prime Minister Yoshihiko Noda just before her flight to China.